Anthony Edward Stark is a fictional character primarily portrayed by Robert Downey Jr. in the Marvel Cinematic Universe (MCU) media franchise—based on the Marvel Comics character of the same name—commonly known by his alias, Iron Man. Stark is initially depicted as an industrialist, genius inventor, and former playboy who is CEO of Stark Industries. Initially the chief weapons manufacturer for the U.S. military, he has a change of heart and redirects his technical knowledge into the creation of mechanized suits of armor which he uses to defend Earth.

The Avengers are a team of fictional superheroes and the protagonists of the Marvel Cinematic Universe (MCU) media franchise, based on the Marvel Comics team of the same name created by Stan Lee and Jack Kirby in 1963. Founded by S.H.I.E.L.D. Director Nick Fury, the team is a United States-based organization composed primarily of superpowered and gifted individuals, described as "Earth's Mightiest Heroes", who are committed to the world's protection from a variety of threats. The Avengers are depicted as operating in the state of New York: originally from the Avengers Tower in Midtown Manhattan and subsequently in the Avengers Compound in Upstate New York. Arranged as an ensemble of core MCU characters originally consisting of Tony Stark / Iron Man, Steve Rogers / Captain America, Thor, Bruce Banner / Hulk, Natasha Romanoff / Black Widow, and Clint Barton / Hawkeye, it later expands to include 16 total members. Regarded as an important part of the franchise, they are central to the MCU's first 23 films, collectively known as the Infinity Saga. The Avengers from alternate universes were depicted in subsequent MCU properties across the Multiverse Saga, including appearances in the Disney+ animated series What If...? (2021–present) and Doctor Strange in the Multiverse of Madness (2022). The Avengers are set to return in Avengers 5 (2026) and Avengers: Secret Wars (2027). Both films will be part of the MCU's Phase Six, concluding the Multiverse Saga.